U.S. patent application number 14/242019 was filed with the patent office on 2014-07-31 for ablation devices utilizing exothermic chemical reactions, system including same, and methods of ablating tissue using same.
This patent application is currently assigned to COVIDIEN LP. The applicant listed for this patent is COVIDIEN LP. Invention is credited to JOSEPH D. BRANNAN.
Application Number | 20140214017 14/242019 |
Document ID | / |
Family ID | 45594648 |
Filed Date | 2014-07-31 |
United States Patent
Application |
20140214017 |
Kind Code |
A1 |
BRANNAN; JOSEPH D. |
July 31, 2014 |
ABLATION DEVICES UTILIZING EXOTHERMIC CHEMICAL REACTIONS, SYSTEM
INCLUDING SAME, AND METHODS OF ABLATING TISSUE USING SAME
Abstract
An ablation device includes a handle assembly including a distal
end and a probe extending distally from the distal end of the
handle assembly. The probe includes a heat-transfer portion and at
least one fluid-flow path in fluid communication with the
heat-transfer portion. The handle assembly includes at least one
fluid reservoir in fluid communication with the at least one
fluid-flow path and at least one apparatus configured to cause
fluid flow between the at least one fluid reservoir and the
heat-transfer portion. The probe is configured to apply thermal
energy released by an exothermic chemical reaction that occurs when
fluid from the at least one fluid reservoir is caused to flow to
the heat-transfer portion.
Inventors: |
BRANNAN; JOSEPH D.; (ERIE,
CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
COVIDIEN LP |
MANSFIELD |
MA |
US |
|
|
Assignee: |
COVIDIEN LP
MANSFIELD
MA
|
Family ID: |
45594648 |
Appl. No.: |
14/242019 |
Filed: |
April 1, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12861333 |
Aug 23, 2010 |
8690866 |
|
|
14242019 |
|
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Current U.S.
Class: |
606/28 |
Current CPC
Class: |
A61B 2018/00023
20130101; A61B 2018/00577 20130101; A61B 2018/048 20130101; A61B
2018/068 20130101; A61B 2018/046 20130101; A61B 18/06 20130101 |
Class at
Publication: |
606/28 |
International
Class: |
A61B 18/06 20060101
A61B018/06 |
Claims
1-20. (canceled)
21. A method for ablating tissue, the method comprising:
positioning an ablation device adjacent tissue to be treated, the
ablation device including: a probe including a heat-transfer
portion in communication with at least one of a first fluid-flow
path and a second fluid-flow path, the first fluid-flow path in
communication with a first fluid reservoir, the second fluid-flow
path in communication with a second fluid reservoir, and the
heat-transfer portion in fluid communication with a third fluid
reservoir, contacting a first fluid, from within the first fluid
reservoir, with a second fluid, from within the second fluid
reservoir, to generate an exothermic reaction; receiving a product
of the exothermic reaction in the heat-transfer portion; delivering
thermal energy released from the exothermic reaction to the tissue
to be treated; and receiving the product of the exothermic reaction
in the third fluid reservoir.
22. The method of claim 21 further comprising expelling the first
fluid from the first fluid reservoir, through the first fluid-flow
path, and into the heat-transfer portion.
23. The method of claim 22, wherein expelling the first fluid
includes actuating a first plunger associated with the first fluid
reservoir.
24. The method of claim 23 further comprising generating an
electric signal with a controller unit, the electric signal
controlling actuation of the first plunger.
25. The method of claim 21 further comprising expelling the second
fluid from the second fluid reservoir, through the second
fluid-flow path, and into the heat-transfer portion.
26. The method of claim 25, wherein expelling the second fluid
includes actuating a second plunger associated with the second
fluid reservoir.
27. The method of claim 21 further comprising engaging a mechanical
coupling to actuate a first plunger to expel the first fluid from
the first fluid reservoir and a second plunger to expel the second
fluid from the second fluid reservoir.
28. The method of claim 21 further comprising expelling a coolant
fluid from a coolant fluid reservoir and through a proximal portion
of the probe after delivering thermal energy to the tissue to be
treated.
29. A method for ablating tissue, the method comprising:
positioning an ablation device adjacent tissue to be treated, the
ablation device including: a controller unit; and a probe operably
coupled to the controller unit and including a heat-transfer
portion and at least one fluid-flow path in fluid communication
with the heat-transfer portion, the at least one fluid-flow path in
fluid communication with at least one fluid reservoir; depressing a
user-operable switch electrically coupled to the controller unit to
expel a first fluid from the at least one fluid reservoir to
contact a second fluid in the heat-transfer portion, thereby
generating an exothermic chemical reaction; and delivering thermal
energy released by the exothermic chemical reaction to the tissue
to be treated.
30. The method of claim 29, wherein depressing the user-operable
switch generates an electric signal from the controller unit to
control an operation of at least one actuator.
31. The method of claim 29 further comprising expelling a coolant
fluid from a coolant fluid reservoir and through a proximal portion
of the probe after delivering thermal energy to the tissue to be
treated.
32. The method of claim 29 further comprising energizing the
controller unit with a self-contained power source.
33. The method of claim 32 further comprising providing a signal
indication of a condition of the self-contained power source to a
user.
34. The method of claim 29 further comprising monitoring a fluid
flow of the first fluid expelled from the at least one fluid
reservoir to the heat-transfer portion using a fluid-flow
monitoring system.
35. The method of claim 34 further comprising regulating the fluid
flow using the fluid-flow monitoring system.
36. The method of claim 35 further comprising monitoring a
temperature of the heat-transfer portion using a temperature sensor
in communication with the controller unit.
37. The method of claim 36 further comprising maintaining the
temperature of the heat-transfer portion within a desired
temperature range using the fluid-flow monitoring system.
38. The method of claim 37, wherein maintaining the temperature of
the heat-transfer portion includes decreasing the fluid flow when
the temperature of the heat-transfer portion is above the desired
temperature range and increasing the fluid flow when the
heat-transfer portion is below the desired temperature range.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of and claims
priority to U.S. patent application Ser. No. 12/861,333 filed on
Aug. 23, 2010, the entire contents of which is incorporated herein
by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to ablation devices suitable
for use in tissue ablation applications and, more particularly, to
ablation devices capable of utilizing exothermic chemical
reactions, a system including the same, and methods of ablating
tissue using the same.
[0004] 2. Discussion of Related Art
[0005] Treatment of certain diseases requires the destruction of
malignant tissue growths, e.g., tumors. Tumor treatment depends on
a variety of factors such as the tumor's type, size, location, and
the overall health of the patient. Treatment options may include
hyperthermia therapy to heat and destroy tumor cells, cryoablation
to freeze the tumor to kill the cells, thermochemical ablation
therapy to thermally ablate the tumor by using direct injection of
ethanol or acetic acid using ultrasound or other guidance and, in
some cases, external beam radiation therapy may be used to destroy
tumor cells.
[0006] In the treatment of diseases such as cancer, certain types
of tumor cells have been found to denature at elevated temperatures
that are slightly lower than temperatures normally injurious to
healthy cells. Known treatment methods, such as hyperthermia
therapy, heat diseased cells to temperatures above 41.degree. C.
while maintaining adjacent healthy cells below the temperature at
which irreversible cell destruction occurs. These methods may
involve applying electromagnetic radiation to heat, ablate and/or
coagulate tissue. Treatment may involve inserting ablation probes
into tissues where cancerous tumors have been identified. Once the
probes are positioned, electromagnetic energy is passed through the
probes into surrounding tissue.
[0007] Electrosurgical devices utilizing electromagnetic radiation
have been developed for a variety of uses and applications. A
number of devices are available that can be used to provide high
bursts of energy for short periods of time to achieve cutting and
coagulative effects on various tissues. There are a number of
different types of apparatus that can be used to perform ablation
procedures. Typically, microwave apparatus for use in ablation
procedures include a microwave generator that functions as an
energy source, and a microwave surgical instrument (e.g., microwave
ablation probe) having an antenna assembly for directing the energy
to the target tissue. The microwave generator and surgical
instrument are typically operatively coupled by a cable assembly
having a plurality of conductors for transmitting microwave energy
from the generator to the instrument, and for communicating
control, feedback and identification signals between the instrument
and the generator.
[0008] During certain procedures, it can be difficult to assess the
extent to which the microwave energy will radiate into the
surrounding tissue, making it difficult to determine the area or
volume of surrounding tissue that will be ablated. Tissue ablation
devices capable of directing thermal energy to tissue without the
use of microwave radiation may enable more precise ablation
treatments, which may lead to shorter patient recovery times, fewer
complications from undesired tissue damage, and improved patient
outcomes.
[0009] Tissue ablation devices capable of directing thermal energy
to heat, ablate and/or coagulate tissue without the use of
electromagnetic radiation may enhance device portability and
location independence, and may help to facilitate improved patient
accessibility to hyperthermic treatments.
SUMMARY
[0010] The present disclosure relates to an ablation device
including a handle assembly including a distal end and a probe
extending distally from the distal end of the handle assembly. The
probe includes a heat-transfer portion and at least one fluid-flow
path in fluid communication with the heat-transfer portion. The
handle assembly includes at least one fluid reservoir in fluid
communication with the at least one fluid-flow path and at least
one apparatus configured to cause fluid flow between the at least
one fluid reservoir and the heat-transfer portion. The probe is
configured to apply thermal energy released by an exothermic
chemical reaction that occurs when fluid from the at least one
fluid reservoir is caused to flow to the heat-transfer portion.
[0011] The present disclosure also relates to a system for ablating
tissue including an ablation device capable of utilizing an
exothermic chemical reaction. The ablation device includes a handle
assembly including a cartridge unit and a probe extending distally
from a distal end of the handle assembly. The cartridge unit
includes a first chamber containing a first fluid and a second
chamber containing a second fluid. The probe includes a mixing
junction and first and second fluid-flow paths in fluid
communication with the mixing junction. The first fluid-flow path
is in fluid communication with the first chamber, and the second
fluid-flow path is in fluid communication with the second
chamber.
[0012] The present disclosure also relates to a method of
delivering thermal energy to tissue including the initial step of
providing an ablation device including a handle assembly and a
probe operably coupled to the handle assembly. The probe includes a
heat-transfer portion and at least one fluid-flow path defined
therein and disposed in fluid communication with the heat-transfer
portion. The handle assembly includes at least one fluid reservoir
in fluid communication with the at least one fluid-flow path. The
method also includes the steps of positioning the probe in tissue,
causing an exothermic chemical reaction within the at least one
fluid flow path of the probe, and delivering thermal energy
released by the exothermic chemical reaction through the
heat-transfer portion of the probe to tissue.
[0013] The present disclosure also relates to a method of
delivering thermal energy to tissue including the initial step of
providing an ablation device including a handle assembly and a
probe extending distally from a distal end of the handle assembly.
The handle assembly includes a cartridge housing a first chamber
defined therein and configured to contain an acid and a second
chamber defined therein and configured to contain a base. The probe
includes a mixing junction and first and second fluid-flow paths in
fluid communication with the mixing junction. The first fluid-flow
path is in fluid communication with the first chamber, and the
second fluid-flow path is in fluid communication with the second
chamber. The method also includes the steps of positioning the
probe in tissue, moving one or more moveable members operably
coupled to the cartridge to cause fluid flow of the acid and the
base to the mixing junction to cause an exothermic chemical
reaction, and delivering thermal energy released by the exothermic
chemical reaction through at least a portion of the probe to
tissue.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Objects and features of the presently disclosed ablation
devices utilizing exothermic chemical reactions, system including
the same, and methods of ablating tissue using the same will become
apparent to those of ordinary skill in the art when descriptions of
various embodiments thereof are read with reference to the
accompanying drawings, of which:
[0015] FIG. 1 is a block diagram of a heat-generating system for
carrying out an exothermic chemical reaction to produce thermal
energy according to an embodiment of the present disclosure;
[0016] FIG. 2 is a schematic diagram of an embodiment of an
ablation device capable of utilizing an exothermic chemical
reaction for applying ablative thermal energy to tissue in
accordance with the present disclosure;
[0017] FIG. 3 is a schematic diagram of an ablation system
including an embodiment of an ablation device capable of utilizing
an exothermic chemical reaction for applying ablative thermal
energy to tissue in accordance with an embodiment of the present
disclosure;
[0018] FIG. 4A is a cross-sectional view of a proximal portion of
the probe of the ablation device of FIG. 3 taken along section
lines 4A-4A according to an embodiment of the present
disclosure;
[0019] FIGS. 4B through 4I are cross-sectional views of a
fluid-mixing portion of the probe of the ablation device of FIG. 3
taken along section lines 4B-4B through 4I-4I, respectively,
according to an embodiment of the present disclosure;
[0020] FIGS. 4J and 4K are cross-sectional views of a distal
portion of the probe of the ablation device of FIG. 3 taken along
section lines 4J-4J and 4K-4K, respectively, according to an
embodiment of the present disclosure;
[0021] FIG. 5 is a perspective view of another embodiment of an
ablation device capable of utilizing an exothermic chemical
reaction for applying ablative thermal energy to tissue in
accordance with the present disclosure;
[0022] FIG. 6 is partial, cross-sectional side perspective view of
the indicated area of detail of FIG. 5 according to an embodiment
of the present disclosure;
[0023] FIG. 7A is a cross-sectional view of a proximal portion of
the probe of the ablation device of FIG. 5 including a cooling
jacket disposed thereabout taken along section lines 7A-7A
according to an embodiment of the present disclosure;
[0024] FIGS. 7B through 7H are cross-sectional views of a
fluid-mixing portion of the probe of the ablation device of FIG. 5
including a cooling jacket disposed thereabout taken along section
lines 7B-7B through 7H-7H, respectively, according to an embodiment
of the present disclosure;
[0025] FIGS. 7I through 7K are cross-sectional views of a
heat-transfer portion of the probe of the ablation device of FIG. 5
taken along section lines 7I-7I through 7K-7K, respectively,
according to an embodiment of the present disclosure;
[0026] FIG. 8 is a partial, schematic diagram of an apparatus
capable of generating fluid flow by controlling the position of one
or more pistons within one or more fluid reservoirs of a cartridge
unit according to an embodiment of the present disclosure;
[0027] FIG. 9 is a flowchart illustrating a method of ablating
tissue according to an embodiment of the present disclosure;
and
[0028] FIG. 10 is a flowchart illustrating a method of ablating
tissue according to another embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0029] Hereinafter, embodiments of the presently disclosed ablation
devices utilizing exothermic chemical reactions, system including
the same, and methods of ablating tissue using the same are
described with reference to the accompanying drawings. Like
reference numerals may refer to similar or identical elements
throughout the description of the figures. As shown in the drawings
and as used in this description, and as is traditional when
referring to relative positioning on an object, the term "proximal"
refers to that portion of the apparatus, or component thereof, that
is closer to the user and the term "distal" refers to that portion
of apparatus, or component thereof, that is farther from the
user.
[0030] This description may use the phrases "in an embodiment," "in
embodiments," "in some embodiments," or "in other embodiments,"
which may each refer to one or more of the same or different
embodiments in accordance with the present disclosure. For the
purposes of this description, a phrase in the form "A/B" means A or
B. For the purposes of the description, a phrase in the form "A
and/or B" means "(A), (B), or (A and B)". For the purposes of this
description, a phrase in the form "at least one of A, B, or C"
means "(A), (B), (C), (A and B), (A and C), (B and C), or (A, B and
C)".
[0031] As it is used in this description, "fluid" generally refers
to a liquid, a gas or both. As it is used in this description,
"pressure" generally refers to positive pressure, negative pressure
or both. As it is used in this description, "exothermic chemical
reaction", or "exothermic reaction" for short, generally refers to
a chemical reaction that releases energy in the form of heat.
[0032] As it is used in this description, "acid" generally refers
to any chemical compound that, when dissolved in water, gives a
solution with a hydrogen ion activity greater than in pure water,
e.g., a pH less than 7.0 (at 25.degree. C.) in its standard state.
The strength of an acid or a base is determined by its ability to
ionize in water. The percent ionization of an acid or base may be
defined as the percent of the total molecules of the acid or base
that react with water to form hydronium or hydroxyl ions. Acids
that ionize 95% or better in water are usually referred to as
strong acids. An acid that ionizes less than 95% in water may be
referred to as a weak acid. There is no clear demarcation line
between strong and weak acids and between strong and weak bases.
Rather there is a continuum in the strengths of each.
[0033] As it is used in this description, "actuator" generally
refers to any device that converts one form of applied power to a
useable form of power that provides motion of a moveable member.
Actuators may be generally classified into hydraulic, pneumatic,
and electro-mechanical actuators. Electro-mechanical actuators
generally include an electric motor and one or more drive train
components to transfer and/or convert power provided by the
electric motor to a moveable member. As it is used in this
description, "switch" or "switches" includes any electrical
actuators, mechanical actuators, electro-mechanical actuators
(rotatable actuators, pivotable actuators, toggle-like actuators,
buttons, etc.) or optical actuators.
[0034] As it is used in this description, "transmission line"
generally refers to any transmission medium that can be used for
the propagation of signals from one point to another. As it is used
in this description, "length" may refer to electrical length or
physical length. In general, electrical length is an expression of
the length of a transmission medium in terms of the wavelength of a
signal propagating within the medium. Electrical length is normally
expressed in terms of wavelength, radians or degrees. For example,
electrical length may be expressed as a multiple or sub-multiple of
the wavelength of an electromagnetic wave or electrical signal
propagating within a transmission medium. The wavelength may be
expressed in radians or in artificial units of angular measure,
such as degrees. The electric length of a transmission medium may
be expressed as its physical length multiplied by the ratio of (a)
the propagation time of an electrical or electromagnetic signal
through the medium to (b) the propagation time of an
electromagnetic wave in free space over a distance equal to the
physical length of the medium. The electrical length is in general
different from the physical length. By the addition of an
appropriate reactive element (capacitive or inductive), the
electrical length may be made significantly shorter or longer than
the physical length.
[0035] Various embodiments of the present disclosure provide
ablation devices capable of utilizing an exothermic chemical
reaction to produce heat for treating tissue and methods of
delivering ablative thermal energy to tissue.
[0036] Various embodiments of the presently disclosed ablation
devices capable of utilizing an exothermic reaction and
electrosurgical systems including the same are suitable for
ablation and for use to pre-coagulate tissue for ablation-assisted
surgical resection. Although various methods described hereinbelow
are targeted toward ablation and the complete destruction of target
tissue, it is to be understood that methods for directing thermal
energy may be used with other therapies in which the target tissue
is partially destroyed or damaged, such as, for example, to prevent
the conduction of electrical impulses within heart tissue.
[0037] It is envisioned and within the scope of the present
disclosure that any combination of battery cells, a battery pack,
fuel cell and/or high-energy capacitor may be used to provide power
to the ablation device (e.g., 101, 102 and 103 shown in FIGS. 2, 3
and 5, respectively). For example, capacitors may be used in
conjunction with a battery pack. In such case, the capacitors may
discharge a burst of power to provide energy more quickly than
batteries are capable of providing, as batteries are typically
slow-drain devices from which current cannot be quickly drawn. It
is envisioned that batteries may be connected to the capacitors to
charge the capacitors.
[0038] A battery pack may include at least one disposable battery.
In such case, the disposable battery may be between about 9 volts
and about 30 volts, and may be useful as a primary power source for
a processor unit (e.g., 226 shown in FIG. 2). In some embodiments,
a transmission line (e.g., 15 shown in FIG. 3) is provided to
connect the ablation device (e.g., 102 shown in FIG. 3) to a line
source voltage or external power source (e.g., 48 shown in FIG. 3),
in which case a battery pack may be used as a backup power
source.
[0039] FIG. 1 shows a schematic of a heat-generating system 10 for
use in carrying out an exothermic reaction to produce thermal
energy (shown generally as "H" in FIG. 1). Heat-generating system
10 generally includes a processor unit 26, a user interface 70
operably associated with the processor unit 26, and an exothermic
reaction unit 11 configured to selectively carry out an exothermic
chemical reaction in which thermal energy is released.
[0040] Exothermic reaction unit 11 includes one or more
controllable actuators (e.g., 31, 32 and 33) operably associated
with one or more fluid reservoirs (e.g., 41, 42 and 43) and/or one
or more fluid flow paths (e.g., 131, 132 and 133), and may be
operably associated with the processor unit 26. The actuators may
be of any suitable type. Examples of types of actuators that may be
suitable include hydraulic actuators, pneumatic actuators, and
electro-mechanical actuators. Processor unit 26 is communicatively
associated with the one or more actuators and adapted to generate
an electric signal for controlling an operation of the one or more
actuators, e.g., to supply force and motion to position one or more
moveable members (e.g., 380 shown in FIG. 3) operably associated
therewith. Logic associated with one or more actuators may control
an operation of the actuator in response to a user-initiated
action. In some embodiments, the user interface 70 includes a
user-operable switch (e.g., 21 shown in FIG. 2) that is
electrically coupled to the processor unit 26. A user-operable
switch may additionally, or alternatively, be mechanically coupled
to one or more actuators for selectively generating a fluid flow
when mechanical force is applied thereto.
[0041] In some embodiments, the user interface 70 may include a
fluid-flow monitoring system adapted to monitor and/or regulate the
pressure and/or flow rate of fluid and capable of generating a
signal indicative of an abnormal fluid-flow condition. User
interface 70 may additionally, or alternatively, include audio
and/or visual indicator devices. User feedback may be included in
the form of pulsed patterns of light, acoustic feedback (e.g.,
buzzers, bells or beeps that may be sounded at selected time
intervals), verbal feedback, and/or haptic vibratory feedback (such
as an asynchronous motor or solenoids), for example.
[0042] Processor unit 26 is operably associated with a power source
16, e.g., a battery pack. Processor unit 26 may include any type of
computing device, computational circuit, or any type of processor
or processing circuit capable of executing a series of instructions
that are stored in a memory (not shown) of the processor unit 26.
The series of instructions may be transmitted via propagated
signals for execution by the processor unit 26 for performing the
functions described herein and to achieve a technical effect in
accordance with the present disclosure. It is envisioned and within
the scope of the present disclosure that the heat-generating system
10 may include a temperature sensor, e.g., a thermocouple, which
may be monitored by the processor unit 26.
[0043] Heat-generating system 10 according to an embodiment of the
present disclosure includes a first actuator 31 operably associated
with a first fluid flow path 131, a second actuator 32 operably
associated with a second fluid flow path 132, and a third actuator
33 operably associated with a third fluid flow path 133. First
fluid flow path 131 is in fluid communication with a first
reservoir 41. First reservoir 41 is capable of containing a
quantity of a first fluid "F1", and may be capable of holding the
first fluid "F1" under pressure. Second fluid flow path 132 is in
fluid communication with a second reservoir 42. Second reservoir 42
is capable of containing a quantity of a second fluid "F2", and may
be capable of holding the second fluid "F2" under pressure. Third
fluid flow path 133 is in fluid communication with a third
reservoir 43, which is capable of containing a quantity of a third
fluid "F3".
[0044] First fluid "F1" and the second fluid "F2" may include any
reagent or reactant suitable for use in an exothermic reaction to
produce thermal energy for treating tissue, e.g., ablative thermal
energy. The portion of the first fluid "F1" that serves as a
reactant (e.g., readable with the second fluid "F2" to produce an
exothermic reaction) may be referred to herein as a "first reactant
portion", and the portion of the second fluid "F2" that serves as a
reactant (e.g., reactable with the first fluid "F1" to produce an
exothermic reaction) may be referred to herein as a "second
reactant portion".
[0045] In some embodiments, the first fluid "F1" may be an acid and
the second fluid "F2" may be a base. It will be appreciated that
the first fluid "F1" may be a base and the second fluid "F2" may be
an acid. Third fluid "F3" may include products of a reaction, e.g.,
an acid-base reaction, between the first fluid "F1" and the second
fluid "F2". In some embodiments, the third fluid "F3" may be a
coolant fluid, e.g., water or saline.
[0046] In some embodiments, the first fluid "F1" includes a strong
acid, and the second fluid "F2" may include a weak base. Substances
that ionize 95% or better in water are usually referred to as
strong acids. Examples of strong acids include hydrochloric acid
(HCl), hydrobromic acid (HBr), hydroiodic acid (HI), sulfuric acid
(H.sub.2SO.sub.4), nitric acid (HNO.sub.3), chloric acid
(HClO.sub.3) and perchlorie acid (HClO.sub.4). Examples of weak
bases include alanine (C.sub.5H.sub.5NH.sub.2), ammonia (NH.sub.3),
methylamine (CH.sub.3NH.sub.2) and pyridine (C.sub.5H.sub.5N). In
some embodiments, the second fluid "F2" includes a strong base, and
the first fluid "F1" may include a weak acid. Examples of strong
bases include potassium hydroxide (KOH), barium hydroxide
(Ba(OH).sub.2), caesium hydroxide (CsOH), sodium hydroxide (NaOH),
strontium hydroxide (Sr(OH).sub.2), calcium hydroxide
(Ca(OH).sub.2), lithium hydroxide (LiOH), rubidium hydroxide (RbOH)
and magnesium hydroxide (Mg(OH).sub.2). Examples of weak acids
include acetic acid (CH.sub.3COOH) and oxalic acid
(H.sub.2C.sub.2O.sub.4).
[0047] In some embodiments, the first fluid "F1" includes HCl and
the second fluid "F2" includes any suitable metal oxides reactable
with HCl to produce an exothermic reaction. In one embodiment, the
first fluid "F1" includes hydrochloric acid (HCl), the second fluid
"F2" includes sodium hydroxide (NaOH), and the third fluid "F3"
includes water (H.sub.2O) and salt (NaCl) produced by the HCl+NaOH
reaction. It is envisioned and within the scope of the present
disclosure that other chemical compounds and substances reactable
to produce an exothermic reaction may be utilized by the presently
disclosed heat-generating system 10. For example, other substances
reactable to produce an exothermic reaction may include
Na(s)+0.5Cl.sub.2(s).fwdarw.NaCl(s)+heat in an amount of 411
kilojoules (kJ) per mole of NaCl produced.
[0048] As illustrated in FIG. 1, the flow of the first fluid "F1"
through the first fluid flow path 131 and the flow of the second
fluid "F2" through the second fluid flow path 132 merge at a mixing
junction 60. Upon mixing of the first and second fluids "F1" and
"F2", a chemical reaction occurs that releases thermal energy
(shown generally as "H" in FIG. 1), e.g., sufficient to cause
localized tissue heating around a portion 133a of the third fluid
flow path 133. In some embodiments, a quantity of a first reactant
portion may be mixed with a quantity of a second reactant portion
to control the reaction rate and/or provide a
temperature-controlled ablation procedure, e.g., by controlling the
range of temperature between minimum and maximum temperature and/or
the rate of change of temperature. In some embodiments, the first
reactant portion and/or the second reactant portion may be limited
to a quantity that produces only the desired amount of heat. In
some embodiments, the quantity of the first reactant portion is
exceeded by the quantity of the second reactant portion. For
example, in the case of Na+0.5Cl.sub.2.fwdarw.NaCl, if the quantity
of sodium is doubled while the quantity of chlorine is not
increased, such that 2Na+0.5Cl.sub.2.fwdarw.NaCl+Na, then the
quantity of chlorine limits the reaction.
[0049] FIG. 2 shows an ablation device 101 configured to utilize an
exothermic chemical reaction for applying ablative thermal energy
to tissue according to an embodiment of the present disclosure that
includes an applicator or probe 100. Ablation device 101 generally
includes a handle assembly 200 including a grip portion 275 and a
handle body 273 configured to support the probe 100 at a distal end
3 thereof. Handle assembly 200, according to various embodiments,
may be fabricated from metals, plastics, ceramics, composites,
e.g., plastic-metal or ceramic-metal composites, or other
materials. The shape and size of the handle assembly 200 and the
probe 100 may be varied from the configuration depicted in FIG.
2.
[0050] Probe 100 generally includes one or more fluid flow paths
(e.g., 52, 55 and 58 shown in FIG. 2) configured to allow mixing
and/or delivery of fluid to a heat-transfer portion 12 of the probe
100. Probe 100 may be configured to be detachably mountable to the
distal end 3 of handle body 273, and may be disposable. In some
embodiments, the ablation device 101 may be configured to allow for
replacement of the cartridge unit 40 and/or the probe 100.
[0051] Probe 100, or portion thereof, includes a
thermally-conductive material, such as, for example, copper,
stainless steel, titanium, titanium alloys such as nickel-titanium
and titanium-aluminum-vanadium alloys, aluminum, aluminum alloys,
tungsten carbide alloys or combinations thereof. In some
embodiments, the probe 100, or portion thereof, may be provided
with an outer jacket (not shown) disposed at least partially
thereabout. The outer jacket may be formed of any suitable
material, such as, for example, polymeric or ceramic materials. The
outer jacket may be applied by any suitable method, such as, for
example, heat shrinking, over-molding, coating, spraying dipping,
powder coating, baking and/or film deposition.
[0052] Heat-transfer portion 12 of the probe 100 may be formed of a
high thermally conductive material, e.g., aluminum. Heat-transfer
portion 12 may terminate in a sharp tip 23 to allow for insertion
into tissue with minimal resistance. Heat-transfer portion 12 may
include other shapes, such as, for example, a tip 23 that is
rounded, flat, square, hexagonal, or cylindroconical.
[0053] During an ablation procedure, the probe 100 is inserted into
or placed adjacent to tissue and thermal energy is supplied
thereto. Probe 100 may be placed percutaneously or surgically,
e.g., using conventional surgical techniques by surgical staff. A
clinician may pre-determine the length of time that thermal energy
is to be applied. Application duration may depend on a variety of
factors such as applicator design, number of applicators used
simultaneously, tumor size and location, and whether the tumor was
a secondary or primary cancer. The duration of thermal energy
application using the probe 100 may depend on the progress of the
heat distribution within the tissue area that is to be destroyed
and/or the surrounding tissue. Through limitation of the quantity
of a reactant, the amount of thermal energy generated may be
controlled. The rate of flow of the reactant and/or its
concentration may be adjustable to ensure that only a predetermined
amount of energy is available during one application. Thermal
probes may also be used to monitor and measure temperature of the
reaction product. In some embodiments, a feedback loop may be used
to allow adjustment of the rate of flow and/or concentration of the
reactant(s) based on the measured temperature of the reaction
product.
[0054] Handle body 273 may include a retaining mechanism 14
configured to detachably hold the probe 100. In some embodiments,
the retaining mechanism 14 includes a retainer member that is
movable between at least an engagement position and a released
position. In some embodiments, the ablation device 101 may include
a user-operable switch mechanically coupled to the handle body 273,
e.g., a push button, operable to move the retaining mechanism 14
from an engagement position, in which the retainer member is
engaged with a connector member of the probe 100, to a released
position, in which the retainer member is disengaged from the
connector member of the probe 100.
[0055] Ablation device 101 according to some embodiments includes a
self-contained, power unit 216 and a processor unit 226 that is
electrically coupled to the power unit 216. Ablation device 101 may
be configured to allow for user replacement of the power unit 216.
Power unit 216 may be disposed within the handle assembly 200,
e.g., within the grip portion 275 and/or the handle body 273. For
example, the handle assembly 200 may be equipped with a battery
chamber assessable through a manageable lid. This may include a
screw fastener, snap, or other suitable fasting closure means.
Power unit 216 may include one or more batteries, which may be a
rechargeable type such as a nickel cadmium battery. Ablation device
101 may additionally, or alternatively, be operably coupled to a
line source voltage or external power source (e.g., 48 shown in
FIG. 3). Processor unit 226 is similar to the processor unit 26 of
FIG. 1 and further description thereof is omitted in the interests
of brevity.
[0056] Ablation device 101 includes a user-operable trigger
mechanism or switch 21 that is operably associated with the
processor unit 226. Processor unit 226 may control an operation of
an actuator unit 30 in response to the activation of the switch 21.
In an embodiment, the user-operable switch 21 includes a trigger
211 located within a trigger guard 212. The shape and size of the
trigger 211 and the trigger guard 212 may be varied from the
configuration depicted in FIG. 2. Switch 21 may utilize any
suitable switch configuration. Examples of switch configurations
that may be suitable for use with the ablation device 101 include,
but are not limited to, pushbutton, toggle, rocker (e.g., 521 shown
in FIG. 5), tactile, snap, rotary, slide, and thumbwheel. As an
alternative to, or in addition to, the switch 21, the ablation
device 101 may include voice input technology, which may include
hardware and/or software incorporated in the processor unit 226, or
a separate digital module connected to the processor unit 226. The
voice input technology may include voice recognition, voice
activation, voice rectification, and/or embedded speech.
[0057] Ablation device 101 includes a first fluid-flow path 50 and
a second fluid-flow path 53, and may include a third fluid-flow
path 56. In some embodiments, a portion 51 of the first fluid-flow
path 50, a portion 54 of the second fluid-flow path 53, and a
portion 57 of the third fluid-flow path 56 are disposed within the
handle assembly 200, and a portion 52 of the first fluid-flow path
50, a portion 55 of the second fluid-flow path 53, and a portion 58
of the third fluid-flow path 56 are disposed within the probe 100.
Ablation device 101 may be provided with one or more connectors
configured to releasably couple the portions 51, 52 of the first
fluid-flow path 50, the portions 54, 55 of the second fluid-flow
path 53, and/or the portions 57, 58 of the third fluid-flow path
56.
[0058] Ablation device 101 includes an actuator unit 30 that is
operably associated with a cartridge unit 40. Actuator unit 30 may
additionally be operably associated with the power unit 216 and/or
other power source. Actuator unit 30 generally includes one or more
actuators. In some embodiments, the processor unit 226 is
communicatively associated with the one or more actuators and
adapted to generate an electric signal for controlling an operation
of the one or more actuators. In an embodiment, the actuator unit
30 includes a first actuator 231 operably associated with a first
reservoir 241, a second actuator 232 operably associated with a
second reservoir 242, and a third actuator 233 operably associated
with a third reservoir 243. First, second and third actuators 231,
232 and 233 and the first, second and third reservoirs 241, 242 and
243 are similar to the first, second and third actuators 31, 32 and
33 and the first, second and third reservoirs 41, 42 and 43,
respectively, shown in FIG. 1, and further description thereof is
omitted in the interests of brevity.
[0059] FIG. 3 shows an ablation system 20 including an embodiment
of an ablation device 102 capable of utilizing an exothermic
chemical reaction for applying ablative thermal energy to tissue in
accordance with the present disclosure. Ablation device 102
generally includes a handle assembly 300 including a grip portion
375 and a handle body 373 configured to support an applicator or
probe 110 at a distal end 7 thereof. It will be understood,
however, that other probe embodiments (e.g., 103 shown in FIG. 5)
may be used.
[0060] In some embodiments, the ablation device 102 is electrically
connected via a transmission line 15 to a connector 17, which may
further operably connect the ablation device 102 to a line source
voltage or external power source 48. Transmission line 15 may
additionally, or alternatively, provide a conduit (not shown)
configured to provide coolant from a coolant source 18 to the probe
110.
[0061] During a procedure, e.g., an ablation procedure, using the
electrosurgical system 20, the probe 110 is inserted into or placed
adjacent to tissue and thermal energy is supplied thereto.
Ultrasound or computed tomography (CT) guidance may be used to
accurately guide the probe 110 into the area of tissue to be
treated. A plurality of probes 110 may be placed in
variously-arranged configurations to substantially simultaneously
ablate a target tissue region, making faster procedures possible.
Multiple probes 110 may be used to synergistically create a large
ablation or to ablate separate sites simultaneously. Probe 110
generally includes one or more fluid flow paths configured to allow
mixing and/or delivery of fluid to a heat-transfer portion 365 of
the probe 110.
[0062] Ablation device 102 includes a processor unit 326, which may
be operably associated with the power unit 316 and/or the external
power source 48. Processor unit 326 is similar to the processor
unit 26 of FIG. 1 and further description thereof is omitted in the
interests of brevity.
[0063] Ablation device 102 includes an actuator unit 330. Actuator
unit 330 may include any suitable number of actuators. Actuator
unit 330 is operably associated with a cartridge unit 340. Probe
100 generally includes a plurality of fluid-flow paths in fluid
communication with the cartridge unit 340 via a plurality of
fluid-flow paths (e.g., 350, 353, 356 and 359) disposed within the
handle assembly 300. Actuator unit 330 according to an embodiment
of the present disclosure includes a first actuator 331 operably
associated with a first fluid flow path 350, a second actuator 332
operably associated with a second fluid flow path 353, a third
actuator 333 operably associated with a third fluid flow path 356,
and a fourth actuator 334 operably associated with a fourth fluid
flow path 359.
[0064] Cartridge unit 340 includes a first reservoir 341, a second
reservoir 342 and a third reservoir 343, and may include a fourth
reservoir 344. In some embodiments, the cartridge unit 340 is
similar to the cartridge unit 40 of FIG. 1, except that the
cartridge unit 340 includes a fourth reservoir 344 that is
configured to contain a coolant fluid, e.g., water, in fluid
communication with a fourth fluid-flow path 359.
[0065] As shown in FIG. 4A, a proximal portion of the probe 110 may
be provided with a fluid-flow path for conveying an acid, A, flow
therein; a fluid-flow path for conveying a base, B, flow therein; a
plurality of fluid-flow paths for conveying water, W, flow therein;
and a fluid-flow path for conveying flow of a product, P, e.g.,
formed during an exothermic chemical reaction. FIGS. 4B through 4I
show an embodiment of fluid-flow paths forming a fluid-mixing
portion 360 (shown in FIG. 3) of the probe 110 in accordance with
the present disclosure. An embodiment of a fluid-flow path for
conveying flow of the product, P, within a distal portion of the
probe 110 is shown in FIGS. 4J and 4K. The shape, size and relative
spacing of the fluid-flow paths of the probe 110 may be varied from
the configurations depicted in FIGS. 4A through 4K.
[0066] In other embodiments, the probe 110, or portion thereof, may
be provided with an outer coolant chamber (e.g., 715 and 716 shown
in FIG. 7A). Additionally, the probe 110 may include coolant inflow
and outflow ports (not shown) to facilitate the flow of coolant
into, and out of, the coolant chamber. Examples of coolant chamber
and coolant inflow and outflow port embodiments are disclosed in
commonly assigned U.S. patent application Ser. No. 12/401,268 filed
on Mar. 10, 2009, entitled "COOLED DIELECTRICALLY BUFFERED
MICROWAVE DIPOLE ANTENNA", and U.S. Pat. No. 7,311,703, entitled
"DEVICES AND METHODS FOR COOLING MICROWAVE ANTENNAS".
[0067] FIG. 5 shows an ablation device 103 capable of utilizing an
exothermic chemical reaction for applying ablative thermal energy
to tissue according to an embodiment of the present disclosure.
Ablation device 103 generally includes a handle assembly 500
including a grip portion 575 and a handle body 573 configured to
support an applicator or probe 1000 at a distal end thereof. Handle
assembly 500 includes a controller 526, a switch 521, and an
indicator unit 520 including one or more light-emitting elements
(e.g., 221 and 222). The shape and size of the handle assembly 500
and the probe 1000 may be varied from the configuration depicted in
FIG. 5.
[0068] Switch 521 may be any suitable switch that generally
fulfills the purpose of switching electrical circuits on and off or
switching over from one electrical circuit to another. In the
embodiment illustrated in FIG. 5, the switch 521 is a rocker-type
switch that generally includes two wing portions projecting from
opposite sides of a rotational axis for alternatingly engaging
depressible operators of the switch 521. The shape, size and
location of the switch 521 may be varied from the configuration
depicted in FIG. 5
[0069] In an embodiment, the indicator unit 520 may include a first
LED 221 and a second LED 222. In some embodiments, a change in
color of the first LED 221 and/or the second LED 222 may be used to
indicate a user-initiated action and/or to signal
temperature-related information. Indicator unit 520 may be used to
signal the occurrence of an abnormal fluid-flow condition, or other
condition, e.g., low-battery condition.
[0070] Ablation device 103 includes an actuator unit 530 that is
operably associated with a cartridge unit 540. Cartridge unit 540
includes one or more reservoirs configured to contain fluids
therein, e.g., three or four reservoirs, and may be formed of any
suitable material. Cartridge unit 540 may be adapted to be
removeably coupleable to an actuator 540. The reservoirs may have
any suitable size, shape and capacity or storage volume. In an
embodiment, the cartridge unit 540 includes a first reservoir
configured to contain a first fluid, e.g., an acid, a second
reservoir configured to contain a second fluid, e.g., a base, a
third reservoir configured to contain a third fluid, e.g., water or
saline, and a fourth reservoir configured to receive a flow of a
fourth fluid, e.g., water and/or a product of an exothermic
chemical reaction. The capacity of the fourth reservoir may be
sufficient to allow the fourth reservoir to receive and contain the
first, second and/or third fluid therein. In various embodiments,
the ablation device 103 may be configured to allow for replacement
of the cartridge unit 540 and/or the probe 1000.
[0071] Probe 1000 generally includes a plurality of fluid-flow
paths in fluid communication with the cartridge unit 540. As shown
in FIG. 6, a proximal portion of the probe 1000 may be provided
with a fluid-flow path for conveying an acid, A, flow therein, a
fluid-flow path for conveying a base, B, flow therein, a fluid-flow
path for conveying flow of a product, P, e.g., formed during an
exothermic chemical reaction, and an outer coolant chamber
including first and second portions 626 and 628 for conveying water
flow therein.
[0072] FIG. 8 shows an apparatus capable of generating fluid flow
by controlling the position of one or more pistons or plungers
(e.g., "P1", "P2" and "P3") within one or more fluid reservoirs
(e.g., 541, 542 and 543) of a cartridge unit 540 according to an
embodiment of the present disclosure. Cartridge unit 540 is
operably associated with an actuator unit 530. Actuator unit 530 is
operably associated with a processor unit 26, and may include any
number of actuators of any suitable type, e.g., electromechanical
actuators. Actuator unit 530 may include stepper motors and various
servo motors, coupled with gears. In an embodiment, a first plunger
"P1" is mechanically coupled to a first actuator 531 through a
mechanical coupling, a second plunger "P2" is mechanically coupled
to a second actuator 532 through a mechanical coupling, and a third
plunger "P3" is mechanically coupled to a third actuator 533
through a mechanical coupling.
[0073] Under the control of the processor unit 26, the first
actuator 531 causes the first plunger "P1" to expel a volume of a
first fluid "F1" contained within the first reservoir 541, and the
second actuator 532 causes the second plunger "P2" to expel a
volume of a second fluid "F2" contained within the second reservoir
542. In an alternative embodiment, one actuator may be mechanically
coupled to both the first and second plungers "P1" and "P2",
instead of the first and second actuators 531 and 532 shown in FIG.
8. In some embodiments, under the control of the processor unit 26,
the third actuator 533 causes the third plunger "P3" to expel a
volume of a third fluid "F3", e.g., water, and/or to collect a
volume of a product formed during an exothermic chemical
reaction.
[0074] Hereinafter, methods of delivering thermal energy to tissue
are described with reference to FIGS. 9 and 10. It is to be
understood that the steps of the methods provided herein may be
performed in combination and in a different order than presented
herein without departing from the scope of the disclosure.
[0075] FIG. 9 is a flowchart illustrating a method of delivering
thermal energy to tissue according to an embodiment of the present
disclosure. In step 910, an ablation device (e.g., 101 shown in
FIG. 2) is provided. The ablation device (e.g., 101 shown in FIG.
2) includes a handle assembly (e.g., 200 shown in FIG. 2) and a
probe (e.g., 100 shown in FIG. 2) operably coupled to the handle
assembly. The probe (e.g., 101 shown in FIG. 2) includes a
heat-transfer portion (e.g., 12 shown in FIG. 2) and one or more
fluid-flow paths (e.g., 50, 53 and 56 shown in FIG. 2) in fluid
communication with the heat-transfer portion. The handle assembly
(e.g., 200 shown in FIG. 2) includes one or more fluid reservoirs
(e.g., 241, 242 and 243 shown in FIG. 2) in fluid communication
with the one or more fluid-flow paths (e.g., 50, 53 and 56 shown in
FIG. 2).
[0076] In step 920, the probe (e.g., 100 shown in FIG. 2) is
positioned in tissue. The probe may be inserted directly into
tissue, inserted through a lumen, e.g., a vein, needle or catheter,
placed into the body during surgery by a clinician, or positioned
in the body by other suitable methods.
[0077] In step 930, an exothermic chemical reaction is caused
within the one or more fluid-flow paths (e.g., 52, 55 and 58 shown
in FIG. 2) of the probe (e.g., 100 shown in FIG. 2). The step 930
of causing an exothermic chemical reaction within the one or more
fluid-flow paths (e.g., 350, 353, 356 and 359 shown in FIG. 3) of
the probe (e.g., 110 shown in FIG. 3) may include causing fluid
flow of an acid and a base to a mixing junction (e.g., 360 shown in
FIG. 3) of the probe (e.g., 110 shown in FIG. 3). In some
embodiments, the acid may be selected from the group consisting of
hydrochloric acid (HCl), hydrobromic acid (HBr), hydroiodic acid
(HI), sulfuric acid (H.sub.2SO.sub.4), nitric acid (HNO.sub.3),
chloric acid (HClO.sub.3) and/or perchloric acid (HClO.sub.4). In
some embodiments, the base may be selected from the group
consisting of potassium hydroxide (KOH), barium hydroxide
(Ba(OH).sub.2), caesium hydroxide (CsOH), sodium hydroxide (NaOH),
strontium hydroxide (Sr(OH).sub.2), calcium hydroxide
(Ca(OH).sub.2), lithium hydroxide (LiOH), rubidium hydroxide (RbOH)
and/or magnesium hydroxide (Mg(OH).sub.2).
[0078] In step 940, thermal energy released by the exothermic
chemical reaction is delivered through the heat-transfer portion
(e.g., 12 shown in FIG. 2) of the probe (e.g., 100 shown in FIG. 2)
to tissue. Products of the exothermic reaction may be directed away
from the heat-transfer portion (e.g., 12 shown in FIG. 2) via a
fluid-flow path (e.g., 56 shown in FIG. 2) in fluid communication
with a fluid reservoir (e.g., 243 shown in FIG. 2) disposed in the
handle assembly (e.g., 200 shown in FIG. 2).
[0079] FIG. 10 is a flowchart illustrating a method of delivering
thermal energy to tissue according to an embodiment of the present
disclosure. In step 1010, an ablation device (e.g., 102 shown in
FIG. 3) is provided. The ablation device (e.g., 102 shown in FIG.
3) includes a handle assembly (e.g., 300 shown in FIG. 3) and a
probe (e.g., 110 shown in FIG. 3) extending from a distal end
(e.g., 7 shown in FIG. 3) of the handle assembly. The handle
assembly includes a cartridge unit (e.g., 340 shown in FIG. 3)
housing a first chamber (e.g., 341 shown in FIG. 3) containing a
first fluid, e.g., an acid, and a second chamber (e.g., 342 shown
in FIG. 3) containing a second fluid, e.g., a base. The probe
(e.g., 110 shown in FIG. 3) includes a mixing junction (e.g., 360
shown in FIG. 3) and first and second fluid-flow paths (e.g., 350
and 353 shown in FIG. 3) in fluid communication with the mixing
junction. The first fluid-flow path (e.g., 350 shown in FIG. 3) is
in fluid communication with the first chamber (e.g., 341 shown in
FIG. 3), and the second fluid-flow path (e.g., 353 shown in FIG. 3)
is in fluid communication with the second chamber (e.g., 342 shown
in FIG. 3).
[0080] In step 1020, the probe (e.g., 110 shown in FIG. 3) is
positioned in tissue. Ultrasound, computed tomography (CT)
guidance, or other guidance may be used to accurately guide the
probe into the area of tissue to be treated.
[0081] In step 1030, one or more moveable members (e.g., 380 shown
in FIG. 3) operably coupled to the cartridge unit (e.g., 340 shown
in FIG. 3) are moved to cause fluid flow of the acid and the base
to the mixing junction (e.g., 360 shown in FIG. 3) to cause an
exothermic chemical reaction.
[0082] In step 1030, thermal energy released by the exothermic
chemical reaction is delivered through at least a portion of the
probe (e.g., 110 shown in FIG. 3) to tissue.
[0083] The above-described tissue ablation devices and system
including the same are capable of directing thermal energy to heat,
ablate and/or coagulate tissue without the use of electromagnetic
radiation. The capability to provide ablative thermal heat without
the use of electromagnetic radiation may enhance device portability
and location independence, and may help to facilitate improved
patient accessibility to hyperthermic treatments.
[0084] Although embodiments have been described in detail with
reference to the accompanying drawings for the purpose of
illustration and description, it is to be understood that the
inventive processes and apparatus are not to be construed as
limited thereby. It will be apparent to those of ordinary skill in
the art that various modifications to the foregoing embodiments may
be made without departing from the scope of the disclosure.
* * * * *